This invention relates generally to heat transfer and more specifically to systems with an intermediate fluid which transfer heat by evaporating and condensing, known in the art as heat pipes.
The need for efficient heat transfer devices for systems traveling in outer space is well established. Because heat transfer remote from the atmosphere must depend almost completely upon radiation, a frequent goal has been that of maximizing surface area while minimizing the weight and volume occupied during the time when the system is being lifted into space.
One approach to that goal is shown in U.S. Pat. No. 3,496,995 in which a conventional, pumped liquid heat exchange system uses adjacent parallel unfurlable tubes through which cooling liquid is circulated. A second approach in the same patent uses an evaporating-condensing system in an unfurlable tube, but requires gravity to return the condensed liquid to the evaporator. Such systems, requiring either a mechanical pump or a gravity environment, do not satisfactorily fulfill the need for a heat exchange system for space use which is both light weight and gravity independent.
It is therefore an object of this invention to furnish an unfurlable evaporating-condensing heat exchanger which can operate independent of gravity and independent of its orientation relative to any pseudo-gravity, such as that created by centrifugal force.
It is a further object of this invention to provide a structurally self-supporting heat transfer panel with essentially isothermal design, which can be stored rolled up, and will unfurl automatically when heat is applied to the exposed end.
It is a still further object of this invention to provide an unfurlable heat transfer system which is capable of transferring heat bi-directionally and in which both ends may function as either evaporators or condensers.